US Patent 5,897,031: Claim Scope, Expiration, and Patent Landscape for Disposable Product Dispensers

US Patent 5,897,031 covers a disposable dispenser container that attaches to a reusable bracket and actuator through tapered mounting channels. Its central innovation is simultaneous mechanical attachment and pump-actuator alignment during downward installation. Additional claims cover a disposable product path, a manually rotated valve, an integrated pump chamber, venting, a one-way ball valve, and a piston-driven dispensing mechanism.

The patent is a mechanical dispensing patent, not a drug-composition patent. It does not protect a therapeutic ingredient, formulation, dosage regimen, or biologic. Its statutory patent term has expired, so it no longer creates an enforceable exclusivity barrier in the United States. The technical concepts remain relevant to freedom-to-operate analyses involving disposable sanitizer, antimicrobial, soap, lotion, foam, and other fluid cartridges, but current risk would arise from later patents, not from US 5,897,031 itself.[1][2]

What does US Patent 5,897,031 protect?

The patent protects combinations of four principal elements:

A reservoir containing a product.
A pump and outlet for dispensing the product.
A disposable or replaceable container assembly.
A mechanical interface that attaches the container to a reusable bracket and aligns the pump with a movable actuator.

The strongest recurring limitation is the downward attachment mechanism. The container has channels that receive mounting flanges on the reusable dispenser. The channels taper toward one another in the direction of attachment, guiding the pump's driven surface into alignment with the actuator as the container moves vertically downward.

This combination distinguishes the claimed system from a conventional bottle, threaded cartridge, snap-fit package, or pump that must be separately aligned after installation.

Core technical architecture

Technical element	Claims principally covering it	Scope
Reservoir and product outlet	1, 12, 17, 22, 26, 31	Product-containing disposable container
Pump driven by reusable actuator	1, 12, 17, 22, 26, 30, 31	Pump receives force from dispenser actuator
Tapered attachment channels	1, 9-12	Container aligns with bracket during downward installation
Reusable bracket with mounting flanges	1, 12, 17	Counterpart structure on dispenser
Automatic pump-actuator alignment	1, 12, 17	Alignment occurs substantially simultaneously with attachment
Disposable product path	8, 16, 19, 22	Fluid path is discarded with container
Rotary valve	4-7, 13-15, 23, 32	Valve moves between sealed and dispensing positions
Approximately 120-degree rotation	7, 15	Narrow valve-position limitation
Integrated pump chamber	22, 26-30	Valve assembly receives pump and defines chamber
Fill hole and vent hole	22, 26-30	Product entry and replacement-air management
One-way valve	27-29	Prevents reverse flow into reservoir
Gravity-biased ball valve	29	Narrow check-valve configuration
Piston and piston seals	30	Actuator-driven piston with vent control

How are the independent claims structured?

The patent has six principal independent claims: 1, 12, 17, 22, 26, and 31. They divide the invention into a container, a method, a complete dispenser, a detailed valve-pump container, a spool-valve container, and a method of operating the valve assembly.

Claim 1: container assembly with tapered channels

Claim 1 is the principal attachment-and-alignment claim. It requires:

A reservoir.
An outlet.
A pump with a driven surface.
A pair of channels receiving mounting flanges.
Downward attachment to the bracket/actuator assembly.
Channels that taper toward one another in the direction of attachment.
Alignment of the pump's driven surface with the actuator during attachment.

A product would not fall within claim 1 merely because it uses a disposable cartridge and a pump. The accused system would need the claimed relationship between the container channels, the bracket flanges, the vertical installation direction, and automatic pump alignment.

Claims 2 through 11 narrow claim 1 by adding structural features:

Claim 2 requires a substantially planar rear wall.
Claim 3 requires smooth top, front, and side surfaces that are substantially free of sudden discontinuities.
Claims 4 through 7 require a movable valve, with claims 5 through 7 focusing on rotation, perpendicular orientation, approximately 120-degree movement, and downward opening.
Claim 8 requires the entire product path to be disposable with the container.
Claims 9 through 11 place the channels in tapered side walls and define channel ends and stop shoulders.

Claim 12: installation method

Claim 12 covers the method of:

Providing the container, pump, and tapered channels.
Moving the container substantially vertically downward.
Engaging the mounting flanges.
Aligning the pump's driven surface with the actuator during installation.

This claim is directed to conduct rather than merely to the physical product. A system may avoid literal infringement if the cartridge is installed through a materially different movement, such as horizontal sliding, front-to-back insertion, rotation, or separate manual alignment.

Claims 13 through 16 add the rotary valve and disposable-path requirements. Claim 16 is particularly narrow because it requires disposing of the entire product path after depletion.

Claim 17: complete dispenser

Claim 17 covers the combination of:

A bracket/actuator assembly.
A movable actuator.
A pair of mounting flanges.
A container assembly.
Attachment and alignment means that automatically align the pump with the actuator.
Vertical downward attachment.

The claim is framed partly in functional language. Its "attachment and alignment means" limitation may implicate 35 U.S.C. §112(f), depending on the claim construction adopted by a court.[3] If construed as a means-plus-function limitation, the relevant structure would be limited to the corresponding flange-and-engagement structures disclosed in the patent and their statutory equivalents, rather than every mechanism that performs attachment and alignment.

Claims 18 through 21 add smooth surfaces, a disposable product path, tapered side walls, and stop surfaces.

Claim 22: integrated valve, pump chamber, and disposable path

Claim 22 is materially different from claim 1. It focuses on the internal valve-pump structure and requires:

A substantially closed reservoir.
A pump driven by an actuator.
A valve assembly with inner surfaces receiving the pump and defining a pump chamber.
Outer sealing surfaces that seal the reservoir.
Externally accessible grasping surfaces.
A fill hole extending between inner and outer surfaces.
A product path entirely within the disposable container.
Manual movement between sealed and dispensing positions.

This claim can reach a cartridge even if the particular attachment mechanism is not the tapered-channel arrangement of claim 1, provided the valve assembly and integrated pump chamber satisfy the listed limitations.

Claim 26: spool valve and cover passageway

Claim 26 adds a specific construction:

A cover receives the reservoir.
The cover defines a passageway.
A spool element is received in that passageway.
The spool rotates between sealed and dispense positions.

Claims 27 through 30 add progressively narrower fluid-control details:

Claim 27 requires coordinated product and vent passageways.
Claim 28 requires a one-way valve in the product passage.
Claim 29 specifies a gravity-biased ball valve.
Claim 30 specifies a piston, driven surfaces, first and second piston seals, and vent control tied to piston position.

These claims are substantially narrower than the broad container-and-pump concepts in claims 1, 12, and 17.

Claim 31: valve-operation method

Claim 31 covers a method that includes:

Providing the specified reservoir, pump, valve, fill hole, and grasping surfaces.
Mounting the valve for movement between sealed and dispense positions.
Loading product into the reservoir.
Storing the valve in the sealed position.
Moving the valve to the dispense position before dispensing.

Claim 32 narrows the operation to rotation.

What are the key claim limitations for infringement analysis?

The limitations most likely to determine infringement are the following:

Downward installation and tapered channels

The claimed attachment is directional. The container must move in a substantially vertically downward direction, and the channels must taper toward one another in that direction. A cartridge that is inserted horizontally, locked with a latch, or attached by a threaded interface may avoid literal infringement of these limitations.

Simultaneous alignment

The claims require alignment of the pump driven surface with the actuator during attachment. A design in which the actuator is aligned only after installation, or in which the pump automatically self-aligns through a flexible coupling, may present a noninfringement position depending on the precise structure and claim construction.

Entirely disposable product path

Claims 8, 16, 19, and 22 require the entire product path between reservoir and outlet to be located inside the disposable container. A design that leaves a reusable outlet tube, valve, manifold, check valve, or fluid conduit in the dispenser can avoid this limitation.

Rotary valve

Claims 4 through 7, 13 through 15, and 23 require a valve that moves between sealed and dispense positions, with several claims requiring rotation. A sliding gate, flexible membrane, duckbill valve, or actuator-controlled pinch valve may fall outside the literal rotary-valve limitations.

Integrated valve and pump chamber

Claims 22 and 26 require the valve assembly to receive the pump and define the pump chamber. A cartridge with a separate pump housing, or a pump chamber formed solely by the reservoir or dispenser housing, may not satisfy this limitation.

Venting and check-valve arrangement

Claims 27 through 30 require specific coordination between the fill hole, vent hole, reservoir plug, piston seals, and one-way valve. These claims are vulnerable to design-around strategies using a separate vent, pressure-equalizing membrane, diaphragm, or non-ball check valve.

What formulations and products are technically covered?

The patent does not claim a specific chemical composition. Claim 24 refers to a reservoir suitable for sterilizing, disinfecting, or antimicrobial product, but that is a container-use limitation rather than a composition claim.

Potential product categories within the technical field include:

Alcohol-based hand sanitizers.
Antimicrobial soaps.
Hospital disinfectants.
Surface-cleaning liquids.
Lotions and creams.
Foaming personal-care products.
Industrial dispensing fluids.
Food-service and institutional hygiene products.

A product's chemical identity would not determine infringement by itself. The decisive issue would be whether the cartridge and dispenser use the claimed mechanical architecture.

When does US Patent 5,897,031 lose exclusivity?

US 5,897,031 is expired based on the 20-year patent term applicable to utility patent applications filed after June 8, 1995.[2] The term runs from the earliest effective nonprovisional filing date, subject to any patent-term adjustment or extension recorded by the USPTO.

Event	Legal significance
Patent application filing	Establishes the statutory term starting point for post-1995 applications
April 27, 1999 issuance	Patent became enforceable if all other requirements were satisfied
Twenty years from earliest effective nonprovisional filing	Baseline expiration point
Current status	Expired; no present enforceable exclusion right

The patent therefore cannot support a current infringement action based solely on its original claims. Any commercial analysis should shift to later continuation, divisional, improvement, or unrelated dispenser patents that may have different expiration dates.

Patent expiration does not eliminate technical relevance. It removes the right to exclude under this patent. It does not grant freedom from later patents covering particular cartridge geometry, valve assemblies, pumps, sensors, antimicrobial compositions, refill authentication, or dispenser control systems.

What is the Orange Book status of US 5,897,031?

US 5,897,031 is not an Orange Book drug patent. The claims are directed to a container assembly, dispenser, pump, valve, and method of use. They do not claim an active pharmaceutical ingredient, drug formulation, method of treating a disease, or drug delivery regimen in the Orange Book sense.

Consequences include:

No Orange Book-listed drug patent protection should be inferred from this patent.
No Hatch-Waxman Paragraph IV certification would ordinarily target this patent.
The patent does not create FDA drug exclusivity.
Its expiration does not affect a drug's NCE, orphan-drug, pediatric, or other regulatory exclusivity.
FDA approval of a product using a dispenser would be analytically separate from patent rights in the dispenser hardware.[4]

Are there Paragraph IV challenges or biosimilar risks?

No conventional Paragraph IV or biosimilar challenge is implicated by this patent.

Paragraph IV litigation concerns listed patents for approved drug products under the Hatch-Waxman framework. US 5,897,031 is a dispenser patent and is not a drug-substance or drug-product patent suitable for the ordinary Orange Book certification process.[4]

Biosimilar risk is also inapplicable. Biosimilar applications concern biological products and rely on the Purple Book framework, not mechanical dispenser patents.[5] A biologic may be sold in a device or cartridge that uses similar dispensing technology, but any biosimilar patent dispute would ordinarily concern the biologic, formulation, manufacturing process, delivery device, or combination-product configuration, not this expired patent.

How strong is the patent estate?

The patent had meaningful historical scope but weak current exclusionary value because it is expired.

Historical strength

The estate was strongest against a product combining:

A disposable reservoir.
A reusable actuator.
Downward cartridge installation.
Tapered guide channels.
Automatic pump alignment.
An internal disposable fluid path.
A rotary valve with integrated pump components.

The multiple claim categories gave the patent holder several enforcement theories: product claims, system claims, and method claims. Claims 22 and 26 also created a second technical center around the spool valve and integrated pump chamber.

Current strength

Factor	Assessment
Claim breadth	Moderate for the specific cartridge architecture
Technical specificity	High, particularly in claims 27-30
Historical design-around exposure	Moderate to high
Current enforceability	None after expiration
Orange Book relevance	None
Biosimilar relevance	None
Generic-drug launch relevance	None
Current FTO significance	Prior-art and technical-history significance only
Value for licensing	Primarily know-how or historical portfolio value, not exclusionary patent value

The broadest practical limitation is not the presence of a pump. It is the combination of the disposable container with the reusable bracket, downward installation, tapered channels, and simultaneous actuator alignment. The narrowest claims are those requiring the spool element, vent-hole alignment, gravity-biased ball, and piston seal arrangement.

What patent litigation affects US 5,897,031?

The supplied claim set does not identify litigation, and the patent's expiration means that any current litigation based solely on these claims would not ordinarily be viable. Historical litigation, reexamination, terminal disclaimer, PTA, ownership transfers, and related continuation proceedings must be distinguished from present enforceability.

The operative legal points are:

Expiration ends the right to obtain prospective infringement relief for future conduct.
Earlier infringement may raise separate limitation and damages issues, but the relevant period is bounded by the patent term and statutory damages rules.
A patent's expiration does not erase its prior-art status.
Later patents in the same technology area may remain enforceable even when the parent patent has expired.

A portfolio review should therefore treat US 5,897,031 as an expired foundational reference and separately map any continuation or improvement patents claiming the same dispenser platform.

Which companies compete in this technology area?

The relevant commercial field includes companies selling institutional and healthcare dispensing systems, such as:

GOJO Industries.
Ecolab.
Kimberly-Clark.
SC Johnson Professional.
Diversey.
3M.
Deb Group and related professional-hygiene businesses.
Rubbermaid Commercial Products.
Essity and Tork.
Medline Industries.

The competitive issue is usually not ownership of this expired patent. It is whether a supplier controls later intellectual property covering:

Proprietary refill geometry.
Closed disposable fluid paths.
Foam-pump architecture.
Electronic dose control.
Touch-free actuation.
Sensor systems.
Refill authentication.
Anti-counterfeit features.
Product-specific valve and venting structures.
Manufacturing methods for molded cartridge components.

A supplier can therefore have a commercially strong dispenser platform while obtaining no current patent leverage from US 5,897,031.

What generic-entry risks exist?

There is no ordinary generic-entry risk because the patent does not cover a drug and is expired. The relevant commercial risk is device substitution or cartridge interoperability.

Potential market-entry scenarios include:

Entry scenario	Risk under US 5,897,031
Copying the expired cartridge geometry	No current infringement liability under this patent
Selling a compatible disposable refill	No current liability under this patent alone
Using a different valve design	Historically useful design-around; currently not necessary for this patent
Using a horizontal or rotational installation path	Avoids key historical limitations
Leaving a reusable fluid path in the dispenser	Avoids disposable-path claims
Launching an antimicrobial formulation	Separate formulation and regulatory analysis required
Selling a complete dispenser with electronic controls	Later device patents may control
Entering a regulated drug-device combination market	FDA and current patent review remain separate

Key Takeaways

US 5,897,031 is a mechanical dispenser patent, not a drug patent.
Its principal invention is a disposable cartridge that attaches downward through tapered channels while aligning its pump with a reusable actuator.
Claims 1, 12, and 17 focus on attachment and alignment.
Claims 22 and 26 focus on an integrated valve, pump chamber, fill hole, spool, and disposable product path.
Claims 27 through 30 cover progressively narrower venting, check-valve, ball-valve, piston, and seal configurations.
The patent is expired under the applicable 20-year utility-patent term.
It has no current Orange Book, Paragraph IV, biosimilar, or drug exclusivity significance.
Current freedom-to-operate risk must be assessed against later dispenser, cartridge, formulation, manufacturing, and combination-product patents.
The patent remains relevant as a technical and prior-art reference for disposable fluid-dispensing systems.

FAQs

Can a company sell a cartridge compatible with the dispenser covered by US 5,897,031?

Yes, the expired patent alone does not bar commercial sale. Later patents, trademarks, trade dress, contractual restrictions, and regulatory requirements may create separate constraints.

Does claim 24 create patent protection for antimicrobial products?

No. Claim 24 limits the reservoir to suitability for sterilizing, disinfecting, or antimicrobial product. It does not claim the antimicrobial compound or formulation.

Can a dispenser avoid the patent by using a different actuator?

Historically, a materially different actuator could avoid some claims, but the actuator relationship remains part of several independent claims. Because the patent is expired, the question has no present infringement consequence under this patent.

Does disposing of the cartridge always satisfy the disposable product-path claims?

No. The entire product path must be located within the disposable container. A reusable tube, valve, conduit, or manifold may prevent satisfaction of the relevant claim limitation.

Is a later patent on a refill cartridge blocked by US 5,897,031?

No. An expired patent cannot block later commercialization, although it may be prior art against later patent claims and may affect novelty or obviousness analysis under applicable law.

References

United States Patent No. 5,897,031, claims 1-32 (issued Apr. 27, 1999).
35 U.S.C. §154(a)(2) (2023). Patent term.
35 U.S.C. §112(f) (2023). Means-plus-function claim limitations.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book.
U.S. Food and Drug Administration. (2024). Purple Book: Database of licensed biological products.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	245935	⤷ Start Trial
Austria	245936	⤷ Start Trial
Australia	3009697	⤷ Start Trial
Canada	2257592	⤷ Start Trial
Canada	2522124	⤷ Start Trial
Germany	69723834	⤷ Start Trial
Germany	69723836	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 5,897,031

Summary for Patent: 5,897,031